COMPONENTS OF QUARTERLY AND YEAR TO DATE NET PERIODIC BENEFIT COSTS (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Qualified Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost, benefits earned during the period	$ 0	$ 0	$ 0	$ 0
Interest cost on projected benefit obligation	378	384	757	769
Expected return on plan assets	(553)	(826)	(1,107)	(1,652)
Amortization of unrecognized transition obligation	0	0	0	0
Amortization of unrecognized prior service cost	0	0	0	0
Amortization of unrecognized net loss	49	44	98	87
Net periodic pension benefit	(126)	(398)	(252)	(796)
Supplemental Pension Plan
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost, benefits earned during the period	0	0	0	0
Interest cost on projected benefit obligation	13	12	26	24
Expected return on plan assets	0	0	0	0
Amortization of unrecognized prior service cost	0	0	0	0
Amortization of unrecognized net loss	1	2	2	4
Net periodic pension benefit	14	14	28	28
Postretirement Plan, Medical and Life
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost, benefits earned during the period	0	0	0	0
Interest cost on projected benefit obligation	3	4	6	7
Expected return on plan assets	0	0	0	0
Amortization of unrecognized prior service cost	(55)	(55)	(110)	(110)
Amortization of unrecognized net loss	23	27	46	55
Net periodic pension benefit	$ (29)	$ (24)	$ (58)	$ (48)